WO1997005307A1 - Process for modifying porosity in sheet made from flash spinning olefin polymer - Google Patents
Process for modifying porosity in sheet made from flash spinning olefin polymer Download PDFInfo
- Publication number
- WO1997005307A1 WO1997005307A1 PCT/US1996/012160 US9612160W WO9705307A1 WO 1997005307 A1 WO1997005307 A1 WO 1997005307A1 US 9612160 W US9612160 W US 9612160W WO 9705307 A1 WO9705307 A1 WO 9705307A1
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- WO
- WIPO (PCT)
- Prior art keywords
- letdown
- ofthe
- spin
- solution
- letdown chamber
- Prior art date
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Classifications
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/11—Flash-spinning
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/70—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres
- D04H1/72—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged
- D04H1/724—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged forming webs during fibre formation, e.g. flash-spinning
Definitions
- This invention relates to flash spinning olefm polymers and more particularly to the process of making sheets by flash spinning and bonding olefin polymer.
- E. I. du Pont de Nemours and Company forms a single phase solution of ethylene polymer and spin agent at high temperature and pressure.
- the single phase solution is directed into a letdown chamber to form a two phase solution wherein one phase is a polymer rich phase and the other is a spin agent rich phase.
- the solution is directed through a spin orifice into a region of much lower pressure and temperature such that the spin agent is flash evaporated and a fibrillated strand of plexifilamentary material is formed.
- the process thereafter includes flattening the strand into a web and directing the web in an oscillating pattern back and forth across a conveyor.
- Other strands are spun at adjacent stations or spin packs which overlap to form an unbonded sheet ofthe plexifilamentary film-fibril webs.
- the sheet is typically consolidated on the conveyor belt and later provided with other finishing steps that make the sheet material particularly useful for a variety of applications.
- Patents 3,081,519 to Blades et al, 3,227,784 to Blades et al, 3,169,899 to Steuber, 3,227,794 to Anderson et al, 3,851,023 to Brethauer et al, 5,123,983 to Marshall, and U.S. Patent Application Serial No. 08/367,367 describe numerous aspects ofthe process for making such material and are incorporated by reference herein.
- Tyvek® As may be noted in the process of making Tyvek® is that it is currently made with a CFC spin agent. As the use of CFC materials will be prohibited, DuPont has revamped the process of manufacture to eliminate CFCs from the process. However, this has proven to be a daunting task. Presently, DuPont is developing a manufacturing process that utilizes normal pentane hydrocarbon as the spin agent. During developmental tests, it was found that the porosity of sheet material made in the test facility was much more porous than material made with the conventional spin agent. As there are a number of applications for Tyvek® which are best served by the conventional porosity, the system must be altered to provide less porous sheet product. Accordingly, it is an object of the present invention to overcome the above noted problems to provide a sheet product having the desired properties and characteristics.
- the foregoing objects are achieved by a process for manufacturing spunbonded olefin sheets made of layers of flash spun plexifilamentary film-fibril webs.
- the process comprises forming a single phase solution of olefm polymer with spin agent at high pressure and temperature and then lowering the pressure ofthe solution in at least one letdown chamber to form a two phase solution.
- the two phase solution is then passed through a plurality of spin orifices to flash evaporate the spin agent and form plexifilamentary film-fibril webs.
- the film-fibril webs are overlaid on a conveyor to form nonwoven sheet material having properties in a predetermined range.
- the process particularly includes the step of inducing a higher scale of recirculation in the letdown chamber.
- Inducing a higher scale of recirculation in the letdown chamber may be accomplished in by a variety of techniques including providing inserts which reduce the length ofthe letdown chamber, inserts which change the deceleration angle in the letdown chamber, a letdown chamber with a length to diameter ratio of less than about six to one, and other geometric alterations or flow altering inserts which widen the range of residence times for the solution passing through the letdown chamber.
- Figure 1 is a generally schematic cross sectional horizontal elevational view of a single spin pack within a spin cell illustrating the formation of a sheet product
- Figure 2 is an enlarged cross sectional view ofthe block within the spin pack illustrating the path ofthe polymer solution into and through the letdown chamber;
- Figure 3 a view similar to Figure 2 wherein a different sized letdown insert, nominally called a "two thirds” letdown insert, is positioned in the block to provide a different configuration for the letdown chamber;
- Figure 4 is a view similar to Figure 3 wherein a second different sized letdown insert, nominally called a "one half letdown insert, is positioned in the block to provide a third different configuration for the letdown chamber;
- Figure 5 is an enlarged cross sectional view ofthe letdown insert, nominally called a "full" letdown insert, in Figure 2;
- Figure 6 is a view similar to Figure 5 ofthe two thirds letdown insert illustrated in Figure 3;
- Figure 7 is a view similar to Figure 5 ofthe one half letdown insert illustrated in Figure 4;
- Figure 8 is a cross sectional view ofthe end fitting ofthe spin block
- Figure 9 is a photographic image of a web produced by a spin pack having a full letdown insert therein as shown in Figures 2 and 5;
- Figure 10 is a photographic image of a web produced by a spin pack having a two thirds down insert therein as shown in Figures 3 and 6;
- Figure 11 is a photographic image of a web produced by a spin pack having a one half insert therein as shown in Figures 4 and 7;
- Figure 12 is a top view photographic image of a single web swath as laid down by a single spin pack onto a moving conveyor belt.
- a spin cell 10 in which a fiber web W is flash spun and formed into a sheet S.
- the illustration ofthe spin cell 10 is quite schematic and fragmentary for purposes of explanation.
- a schematically illustrated spin pack is positioned within the spin cell 10 in the process of spinning the fiber web W. It should be understood that the process of manufacturing Tyvek® sheet material includes the use of a number of additional spin packs similar to spin pack 12 which are arranged in the spin cell 10 spinning and laying down other webs W to be overlapped together.
- the spin pack 12 spins the web from a polymer solution which is provided to the spin pack 12 through a conduit 20.
- the polymer solution is provided at high temperature and pressure so as to be a single phase solution.
- the polymer solution is then admitted through a letdown orifice 22 into a letdown chamber 24. There is a pressure drop through the letdown orifice 22 so that the solution experiences a slightly lower pressure. At this lower pressure, the single phase solution becomes a two phase solution.
- a first phase ofthe two phase solution has a relatively higher concentration of polymer as compared to the polymer concentration ofthe second phase which has a relatively lower concentration of polymer.
- the system operates such that percentage of polymer in the solution is between slightly less than ten percent up to in excess of twenty five percent based on weight and depending on the spin agent.
- the polymer rich phase probably still has more spin agent than polymer on a comparative weight basis. Based on observations, the polymer rich phase appears to be the continuous phase.
- the two phase polymer solution exits through a spin orifice 26 and enters the spin cell 10 which is at much lower temperature and pressure. At such a low pressure and temperature, the spin agent evaporates or flashes from the polymer such that the polymer is immediately formed into a plexifilamentary film-fibril web.
- the baffle 30 further redirects the flattened web along a path that is roughly 90 degrees relative to the axis ofthe spin orifice (generally downwardly in the drawing).
- the baffle 30, as described in other DuPont patents such as those noted above, rotates at high speed and has a surface contour to cause the web W to oscillate in a back and forth motion in the widthwise direction ofthe conveyor belt 15.
- each web W would form a generally sinusoidal patterned swath, broadly covering the belt; however, in actual practice, there is a substantial randomness to the pattem in which the web becomes arranged on the conveyor belt 15.
- the webs tend to collapse, at times, from a spread apart "spider web” like netting of approximately 1 to 8 or more inches in width, into a yam like strand of less than an inch.
- portions in the pattem that are broadly opened up generously covering the belt, while other portions cover only a thin strip ofthe conveyor belt.
- the swath formed by a single web includes many holes or portions which are not filled in.
- the example in Figure 12 was run at 300 yards per minute which is near the upper portion of the speed range. The range is broadly about 25 to 500 or more yards per minute. From Figure 12, it should be clear that the laydown includes some overlay ofthe web swath onto itself with some open portions distributed throughout the swath. However, at slower belt speeds, the swath is better filled in.
- the sheet material is formed from the webs of a number of spin packs.
- the web swaths overlap web swaths of numerous other spin packs, depending on the speed ofthe web impacting the baffle 30 and the rotation speed ofthe baffle.
- the rotation speed ofthe baffle 30 preferably results in a complete oscillation ofthe web being formed at the rate of generally between 60 to 150 cycles per second and the web swaths end up being about one to three feet wide.
- the spin packs are preferably arranged in a staggered configuration along the conveyor direction (or machine direction) so that each spin pack may be laterally offset (widthwise to the belt) in the range of less than an inch up to about five inches from the next closest spin pack.
- the sheet product S will be formed of many overlapping web swaths.
- the sheet At the end ofthe spin cell 10, the sheet has the form of a batt of fibers very loosely attached together.
- the batt is run under a nip roller 16 to consolidate it into the sheet product S and it is then wound up on roll 17.
- the sheet product S is then taken to a finishing facility where it may be subjected to an assortment of processes depending on the end use ofthe material.
- Most Tyvek® sheet end uses are for fully bonded sheet goods. Most people come into contact with fully bonded Tyvek® sheet with envelopes and housewrap. Fully bonded sheet is formed from the sheet product S by pressing it on heated rolls.
- the heat is maintained at a predetermined temperature (depending on the desired characteristics ofthe final sheet product) such that the web bonds together under the pressure to form a sheet that has substantial strength and toughness while maintaining its opaque quality.
- Tyvek® sheet is noted for its tear strength and tensile strength.
- DuPont also measures delamination strength, burst strength, hydrostatic head, breaking strength, and elongation of its many styles of Tyvek® sheet.
- delamination strength is improved by higher bonding temperatures so that the middle portion ofthe sheet becomes fully heated and therefore, more fully bonded to the surface regions ofthe sheet.
- heat tends to shrink the highly oriented molecular structure ofthe fibrils and the surface area ofthe fibrils is reduced. Lower surface area reduces the opacity and the Tyvek® sheet becomes more translucent.
- Tyvek® sheet As noted above, there are many characteristics of Tyvek® sheet that DuPont investigates, monitors and is otherwise interested in continually optimizing for various end use requirements and purposes. For example, the barrier properties of fully bonded sheet are important in many applications, so porosity is measured by the Gurley Hill method. In many years of experience with the CFC spin agent and the recent intensive investigation related to the commercialization of a new spin agent, DuPont engineers have noted that when the webs formed in the spinning process are very fine having lots of fibrils, the Gurley Hill Porosity goes up (meaning that the sheet is less porous). This is consistent with nonwoven sheets made using other technology such as sheets made from spunbonded and melt blown fibers.
- Darcy's law provides scientific prediction ofthe porosity of fabrics based on the diameter ofthe fibers in the fabric.
- Darcy's law is very complicated and would be difficult to explain in this patent, but suffice it to say that Darcy's law also predicts that the smaller the fibers, the smaller the pores and the less porous the sheet.
- the porosity decreases with finer fiber size as one would expect.
- One ofthe modified conditions was the length ofthe letdown chamber. It was found that if the length ofthe letdown chamber were reduced while maintaining its standard diameter, a web having what appear to be fewer and larger fibrils was produced.
- the webs included portions which may be characterized as "bunched fibrils".
- the bunched fibrils at times appeared to be large fibrils and at other times appeared to be comprised of conventional sized fibrils with extremely short tie points preventing the bunched fibrils from being opened up by hand to reveal any type of verifiable fibrillation or characterization.
- such webs would have been expected to have even lower Gurley Hill Porosity Values than was produced in the original configuration. Little attention was given to such poor appearing webs. However, for completeness, the poorly fibrillated webs were bonded for testing.
- the invention relates in part to adjusting the Gurley Hill Porosity Value by modifying the configuration ofthe letdown chamber.
- designing a system for adjusting the length ofthe letdown chamber in a small piece of equipment that operates at high pressure and temperature in a cost effective manner is no simple task.
- the problem has been solved in the present invention by the creation of a set or assortment of inserts which are provided into the spin block.
- Some ofthe letdown orifices include arrangements to accommodate the letdown orifice and, in particular, to position the letdown orifice in such a place as to change the length ofthe letdown chamber 24.
- the spin block 40 includes a tubular passageway 42. Attached at the left end thereof is a spin orifice assembly, generally indicated by the number 50, which is attached to the spin block 40 by screw threads, bolts or other suitable means. Adjacent the other end ofthe spin block 40 is a connector block 44 which has a curved tubular passageway 45 arranged to align with the tubular passageway 42 of the spin block 40 for the passage of polymer solution immediately prior to being spun into the plexifilamentary film-fibril web as described above. A down leg connector 46 is arranged to be connected on the upper portion of connector block 44 and includes a passage 47 which is similarly aligned with curved tubular passageway 45.
- a letdown insert 60 is provided at the interface of spin block 40 and connector block 44 within the respective passageways 42 and 45 thereof.
- the letdown insert 60 includes a letdown orifice plate 61 (best seen in Figure 5) having a letdown orifice 22 therein.
- the letdown orifice plate 61 is preferably oriented with or near the interface plane 41 where the spin block 40 and connector block 44 abut.
- the letdown insert 60 comprises two parts 60A and 60B which are attached by screw threads or other suitable means.
- the letdown orifice plate 61 preferably sits in a recess in one ofthe insert parts 60A or 60B and is held in the recess by the other insert part.
- the letdown orifice plate 61 is presently made of 430 stainless steel, but may also be made of other hard and tough materials including other stainless steels or other suitable metals, tungsten carbide and other ceramics. A tungsten carbide letdown orifice plate is believed to eventually be the preferred arrangement.
- the insert 60 On either side of the letdown orifice plate 61 , the insert 60 includes a tapered wall portion to gradually accelerate the polymer solution through the orifice 22 and decelerate the polymer in the letdown chamber.
- the letdown acceleration wall 62 preferably includes a convergence angle of about 30° with respect to the axis 63 ofthe insert 60 although an angle in the range of about 15° to about 90° may adequately provide a suitable results for the system.
- angles ofthe taper should be taken in general or approximate or average terms as the configuration may, in fact, become much more complex such as a continuous curve, a series of successive tapers or curves or some other shape to obtain essentially the same result.
- a letdown deceleration wall 64 which is similarly tapered.
- Letdown deceleration wall 64 may actually comprise a combination of geometries for the surface in a manner similar to that described above for the acceleration wall 62, and an expression of an angle relative to the axis 63 is intended to cover a number of geometries that substantially approximate the tapered geometry as shown either by appearance or by physical action on the solution moving through the letdown chamber.
- the letdown chamber 24 is generally defined as that portion of passageway 42 from the interior surface ofthe letdown orifice plate 61 to the interior surface ofthe spin orifice plate 51 which includes the spin orifice 26 therein (see Figure 10).
- the letdown chamber 24 is a full length letdown chamber.
- the letdown chamber is less than full length letdown chamber.
- the insert 70 is in the spin block 40 replacing the insert 60.
- Insert 70 is considerably longer than msert 60 and most notably, has the letdown orifice plate 71 in a position considerably closer to the spin orifice plate 51.
- the letdown chamber with the insert 70 is considerably shorter in length than the full length letdown chamber.
- the letdown chamber in this configuration is about two thirds the length ofthe full letdown chamber.
- the insert 60 will hereafter be referred to as the full insert.
- the insert 70 will hereafter be referred to as the two thirds insert.
- the two thirds insert has a more dramatic taper angle for the deceleration wall 74 as compared to the deceleration wall 64 ofthe full insert 60.
- the deceleration wall 74 ofthe two thirds insert 70 is approximately 60° relative to the axis 73 or more preferably in the range of about 50° to about 75°.
- an orifice plate resembling a hypodermic needle and having an effective angle of 180° may likely produce effects similar to those obtained by reducing the length ofthe letdown chamber.
- the angle may be arranged as small as mechanically possible given the length and diameter ofthe letdown chamber rendering a lower limit of approximately five degrees given the conventional dimensions used by DuPont.
- the one half insert 80 which, like the two thirds insert 70, reduces the effective length of the letdown chamber.
- the one half insert 80 also includes a deceleration wall 84 which is planar or approximately 90° to the axis 83.
- Alternative forms ofthe one half insert may include various angles ofthe deceleration wall similar to the two thirds letdown configuration described above.
- Gurley Hill Porosity Values for sheet products is the number of layers that are included in the sheet. The affects of the numbers of layers was not appreciated until experiments were mn to ascertain the cumulative affects ofthe layers of webs. For this discussion, it is important that a number of terms be clearly understood.
- the term "web” has been used and intended to mean a continuous strand of a flash spun plexifilament emanating from a single spin orifice.
- the term “swath” or “web swath” is intended to meai i the web in an arrangement such as formed when the web has been laid ontc a moving conveyor belt or similar device in a back and forth pattem widthw. : se relative to the conveyor belt.
- a “sweep” of a web is a portion ofthe web swath that extends generally from one extreme ofthe back and forth pattern to the other side.
- a retum “sweep” is a sweep that extends back across the web swath in the opposite direction. Thus, it takes two “sweeps” to form a complete cycle ofthe oscillating pattem ofthe web swath.
- the thickness ofthe sheet is formed by numerous individual sweeps, some of which are successive sweeps from the same web and others which are from successive or preceding webs.
- a sheet product of a predetermined basis weight weight per area of fabric
- the rate of fiber production from each spin pack is maintained relatively constant and the conveyor speed is controlled to bring about the desired basis weight.
- the most commonly accepted theory is that there is some type of tackiness ofthe web immediately after it is spun.
- the logical support for the theory is that there is a short time duration between the second sweep of a web laying down on a first sweep as compared to the time it takes for a sweep ofthe next successive web to come into contact with the preceding web. If there is a tackiness, then the webs are interacting or attaching to one another in a way that a higher Gurley Hill Porosity Value is attained in the bonded sheet. It perhaps should be noted that the Gurley Hill Porosity Value ofthe sheet product S is highest immediately after it has been formed in the spin cell.
- the fibrils tend to shrink thereby opening up the sheet product and making it more porous.
- the sheet products formed with fewer web swaths maintain higher Gurley Hill Porosity Values after bonding. This phenomena has created complications for running tests in anticipation of large scale commercial manufacturing where the smaller scale test system is designed to manufacture with fewer numbers of web swaths.
- the webs produced by such configurations may retain some ofthe tackiness theorized to benefit Gurley Hill Porosity.
- the streaky portions ofthe webs are now believed to not be large fibrils, but actually are a collection of small fibrils collected together in a manner that hold a little ofthe spin agent therein retaining some tackiness for moments longer than other configurations.
- the dynamics ofthe solution passing through the letdown chamber may be one key method of obtaining high Gurley Hill Porosity Values, In fact, Gurley Hill Porosity Values have been attained which are higher than that obtained by other comparable processes.
- the dynamics are believed to center around the flow through the letdown chamber such that if smooth, continuous flow is established, the webs tend to be well fibrillated but have lower Gurley Hill Porosity.
- the a range of residence times is broadened or narrowed.
- the two phase solution undertakes a flow characteristic in the letdown chamber wherein a broader range of residence times is attained.
- ranges of residence times is believed to cause portions ofthe created web to have the tackiness which is also believed to create higher Gurley Hill Porosity Values in the sheet product.
- scale of recirculation is also used to mean range of residence times. For example, a higher scale of recirculation in the letdown chamber means that the solution has a broader range of residence in the letdown chamber. This is because there is believed to be zones within the letdown chamber where solution moves quickly therethrough and other portions where the solution lags and may even back up until other dynamic forces cause the solution to move toward and through the spin orifice. As yet there have been no test procedures developed to confirm that such dynamics are indeed occurring.
- letdown chamber geometry which increases the scale of recirculation will provide the less porous sheet product.
- Examples of techniques to increase the scale of recirculation would be to reduce the length to diameter ratio ofthe letdown orifice, to increase the deceleration angle within the letdown chamber, or to otherwise slow portions ofthe flow of solution through the letdown chamber.
- Gurley Hill Test Method The following are a general discussion ofthe testing procedures to collect data for the samples: Gurley Hill Test Method
- Gurley Hill test method is a measure ofthe barrier strength ofthe sheet material for gaseous materials. In particular, it is a measure of how long it takes for a volume of gas to pass through an area of material wherein a certain pressure gradient exists.
- Gurley-Hill porosity is measured in accordance with TAPPI T-460 om-88 using a Lorentzen & Wettre Model 12 ID Densometer. This test measures the time of which 100 cubic centimeters of air is pushed through a one inch diameter sample under a pressure of approximately 4.9 inches of water. The result is expressed in seconds and is usually referred to as Gurley Seconds. ASTM refers to the American Society of Testing Materials and TAPPI refers to the Technical Association of Pulp and Paper Industry.
- Tear Tear strength means Elmendorf tear strength and is a measure ofthe force required to propagate a tear cut in the fabric. The average force required to continue a tongue-type tear in a sheet is determined by measuring the work done in tearing it through a fixed distance.
- the tester consists of a sector-shaped pendulum carrying a clamp which is in alignment with a fixed clamp when the pendulum is in the raised starting position, with maximum potential energy.
- the specimen is fastened in the clamps and the tear is started by a slit cut in the specimen between the clamps.
- the pendulum is then released and the specimen is torn as the moving jaw moves away from the fixed jaw.
- Elmendorf tear strength is measured in accordance with TAPPI-T-414 om-88 and
- Elongation to break of sheet is a measure ofthe amount a sheet stretches prior to failure (breaking)in a strip tensile test.
- a 1.0 inch (2.54 cm) wide sample is mounted in the clamps - set 5.0 inches (12.7 cm) apart - of a constant rate of extension tensile testing machine such as an Instron table model tester.
- a continuously increasing load is applied to the sample at a crosshead speed of 2.0 in min (5.08 cm/min) until failure. The measurement is given in percentage of stretch prior to failure.
- the test generally follows ASTM D 1682-64.
- the spin cell was closed at a pressure of 3.55 inches (gage) of water and a temperature approximately 50 to 55°C.
- the sheet products were bonded in a Palmer bonder with saturated steam at 51 psi.
- the sheets are approximately 28 inches wide, about 1.7 oz./sq. yd. and made with six separate webs.
Landscapes
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Mechanical Engineering (AREA)
- Nonwoven Fabrics (AREA)
- Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
- Chemical Or Physical Treatment Of Fibers (AREA)
- Artificial Filaments (AREA)
Abstract
Description
Claims
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP96925449A EP0842311B1 (en) | 1995-07-28 | 1996-07-24 | Process and device for modifying porosity in sheet made from flash spinning olefin polymer |
JP9507704A JPH11510568A (en) | 1995-07-28 | 1996-07-24 | Method for modifying the porosity of sheets made from flash spun olefin polymers |
DE69612751T DE69612751T2 (en) | 1995-07-28 | 1996-07-24 | METHOD AND DEVICE FOR CHANGING THE POROSITY IN THE PRODUCTION OF A LAYER FROM FLASH-SPREADED OLEFIN POLYMER |
CA002227553A CA2227553A1 (en) | 1995-07-28 | 1996-07-24 | Process for modifying porosity in sheet made from flash spinning olefin polymer |
US10/225,016 US20030000894A1 (en) | 1994-09-12 | 2002-08-21 | Process for treating liquid |
US10/943,378 US20050054881A1 (en) | 1994-09-12 | 2004-09-17 | Process for treating a liquid |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US162695P | 1995-07-28 | 1995-07-28 | |
US60/001,626 | 1995-07-28 | ||
US08/685,368 US5833900A (en) | 1995-07-28 | 1996-07-23 | Process for modifying porosity in sheet made from flash spinning olefin polymer |
US08/685,368 | 1996-07-23 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US08/811,564 Continuation US5965028A (en) | 1994-09-12 | 1997-03-04 | Process for treating a liquid |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1997005307A1 true WO1997005307A1 (en) | 1997-02-13 |
Family
ID=26669290
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1996/012160 WO1997005307A1 (en) | 1994-09-12 | 1996-07-24 | Process for modifying porosity in sheet made from flash spinning olefin polymer |
Country Status (8)
Country | Link |
---|---|
US (1) | US5833900A (en) |
EP (1) | EP0842311B1 (en) |
JP (1) | JPH11510568A (en) |
KR (1) | KR19990035971A (en) |
CA (1) | CA2227553A1 (en) |
DE (1) | DE69612751T2 (en) |
ES (1) | ES2158325T3 (en) |
WO (1) | WO1997005307A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110129907A (en) * | 2018-02-09 | 2019-08-16 | 厦门当盛新材料有限公司 | A kind of flashing apparatus and its spinning process of polyphenylene sulfide |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5971731A (en) * | 1996-11-01 | 1999-10-26 | E. I. Du Pont De Nemours And Company | Nose cone for small spin head in flash spinning system |
KR101627940B1 (en) * | 2014-12-02 | 2016-06-08 | 주식회사 효성 | Spinning nozzle for high pressure injection spinning |
CN115341342B (en) * | 2022-08-24 | 2024-05-07 | 厦门当盛新材料有限公司 | Multi-jet nozzle, flash spinning equipment and flash spinning method |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3484899A (en) * | 1967-04-06 | 1969-12-23 | Du Pont | Spinneret pack for flash extrusion |
US3756441A (en) * | 1972-08-14 | 1973-09-04 | Du Pont | Flash spinning process |
US5147586A (en) * | 1991-02-22 | 1992-09-15 | E. I. Du Pont De Nemours And Company | Flash-spinning polymeric plexifilaments |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL271149A (en) * | 1960-11-08 | 1900-01-01 | ||
US3227664A (en) * | 1961-12-07 | 1966-01-04 | Du Pont | Ultramicrocellular structures of crystalline organic polymer |
US3081519A (en) * | 1962-01-31 | 1963-03-19 | Fibrillated strand | |
NL300881A (en) * | 1962-11-23 | |||
US3851023A (en) * | 1972-11-02 | 1974-11-26 | Du Pont | Process for forming a web |
LU69196A1 (en) * | 1974-01-18 | 1975-12-09 | ||
EP0517693B1 (en) * | 1990-02-26 | 1997-05-02 | E.I. Du Pont De Nemours And Company | Halocarbons for flash-spinning polyethylene plexifilaments |
US5123983A (en) * | 1990-08-24 | 1992-06-23 | E. I. Du Pont De Nemours And Company | Gas management system for closely-spaced laydown jets |
US5286422A (en) * | 1991-08-03 | 1994-02-15 | Asahi Kasei Kogyo Kabushiki Kaisha | Process for producing three-dimensional fiber using a halogen group solvent |
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1996
- 1996-07-23 US US08/685,368 patent/US5833900A/en not_active Expired - Fee Related
- 1996-07-24 CA CA002227553A patent/CA2227553A1/en not_active Abandoned
- 1996-07-24 EP EP96925449A patent/EP0842311B1/en not_active Expired - Lifetime
- 1996-07-24 DE DE69612751T patent/DE69612751T2/en not_active Expired - Fee Related
- 1996-07-24 KR KR1019980700632A patent/KR19990035971A/en not_active Application Discontinuation
- 1996-07-24 JP JP9507704A patent/JPH11510568A/en not_active Ceased
- 1996-07-24 ES ES96925449T patent/ES2158325T3/en not_active Expired - Lifetime
- 1996-07-24 WO PCT/US1996/012160 patent/WO1997005307A1/en not_active Application Discontinuation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3484899A (en) * | 1967-04-06 | 1969-12-23 | Du Pont | Spinneret pack for flash extrusion |
US3756441A (en) * | 1972-08-14 | 1973-09-04 | Du Pont | Flash spinning process |
US5147586A (en) * | 1991-02-22 | 1992-09-15 | E. I. Du Pont De Nemours And Company | Flash-spinning polymeric plexifilaments |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110129907A (en) * | 2018-02-09 | 2019-08-16 | 厦门当盛新材料有限公司 | A kind of flashing apparatus and its spinning process of polyphenylene sulfide |
Also Published As
Publication number | Publication date |
---|---|
KR19990035971A (en) | 1999-05-25 |
DE69612751T2 (en) | 2002-02-28 |
EP0842311A2 (en) | 1998-05-20 |
ES2158325T3 (en) | 2001-09-01 |
CA2227553A1 (en) | 1997-02-13 |
JPH11510568A (en) | 1999-09-14 |
DE69612751D1 (en) | 2001-06-13 |
EP0842311B1 (en) | 2001-05-09 |
US5833900A (en) | 1998-11-10 |
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